Enantiospecific Electrodeposition of Chiral CuO Films on Cu(1 1 0) from Aqueous Cu(II) Tartrate and Amino Acid Complexes

CuO films were anodically electrodeposited onto Cu(110) single crystals from alkaline solutions of Cu(II) complexed with tartrate, alanine, valine, and glycine. In all cases the films were epitaxial, exhibiting varying amounts of the chiral orientations (110) and (110). The enantiomeric excess (ee) of the chiral electrodeposition process was determined by X-ray pole figure analysis. The CuO films deposited from d-tartrate solution exhibited a (110) out-of-plane orientation with an ee of 61%, while films grown from l-tartrate exhibited a (110) orientation with an ee of 77%. The CuO film deposited from achiral meso-tartrate had essentially equal amounts of both chiral orientations. Epitaxial CuO films deposited from d-alanine and d-valine both gave (110) orientation with ee's of 40 and 65%, respectively, while CuO films deposited from l-alanine and l-valine gave (110) orientations with ee's of 39 and 67%, respectively. Films obtained from a glycine solution showed roughly equal amounts of both chiral orientations.